The atmosphere simulation chamber SAPHIR at the Research Centre Jülich was used to test the suitability of state-of-the-art analytical instruments for the measurement of gas-phase formaldehyde (HCHO) in air. Five analyzers based on four different sensing principles were deployed: a differential optical absorption spectrometer (DOAS), cartridges for 2,4-dinitrophenylhydrazine (DNPH) derivatizati...

We have developed a direct amine/acid-catalyzed stereoselective hydrogenation of a variety of Wieland-Miescher (W-M) ketones, Hajos-Parrish (H-P) ketones and their analogs with organic hydrides (Hantzsch esters) as the hydrogen source. This astonishingly simple and biomimetic approach was used to construct highly functionalized chiral bicyclo[4.4.0]decane-1,6-diones in a diastereoselective fash...

Recent studies showed that 1,4-dihydropyridine-3,5-dicarbamoyl derivatives with lipophilic groups have significant antitubercular activity. In this study, we have synthesized new derivatives of 1,4-dihydropyridines bearing carbmethoxy and carbethoxy group at C-3 and C-5 of the 1,4-dihydropyridine ring. In addition, 1H-pyrazole ring is substituted at C-4 position. These analogues were synthesize...

Within the realm of catalytic asymmetric hydrogenation, the focus continues to be on the use of chiral metal complexes in conjunction with a hydrogen source. Recently, the widespread development of organocatalysis, including the invention of iminium activation, has led to the discovery of many new enantioselective transformations. Based on this strategy, a number of bioinspired processes for th...